1. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, Medical Research Council of Canada Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada, Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854, Department of Biochemistry, University of WisconsinMadison, Madison, Wisconsin 53706, and Miami Valley Laboratories, Procter & Gamble Company, Cincinnati, Ohio...